Purchase this article with an account.
Kohei Oka, Toshiaki Miura; Factors that decline a manual dexterity on persons with mental retardation: an analysis of tasks, motions, and eye movements in the time course.. Journal of Vision 2007;7(9):420. doi: 10.1167/7.9.420.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
We investigated what factors cause the decline of a manual dexterity of person(s) with mental retardation (PMR), by analyzing tasks, hand and body motions, and eye movements. We adopted an enclosing task in real work environment. The task was to put two candies (17mm × 17mm × 13mm) into a soft thin plastic bag (with 60mm width and 100mm depth) and fold over so as to close the plastic bag. Most PMR showed difficulty to perform the task with accuracy and speed.
In this study, one PMR (28 years old, male, right-handed, TIQ=35, VIQ=48, PIQ=35) and one person without mental retardation (27 years old, male, right-handed) participated. Participants were instructed to perform as accurately and fast as possible. After sufficient practices, participants performed twenty trials.
We classified actions into subtasks and analyzed the order and duration of actions and fixation points, by using video and eye-mark recorder. Moreover, we analyzed hand and body motion by using a motion capture system.
The result showed that there were four factors that would decline manual dexterity and time performance of PMR. 1) Most of saccades to a target of PMR were delayed at the start of reaching. Meanwhile, the saccades of the control participant were always initiated before the reaching started. 2) The trunk of the body of PMR was more unstable, and shoulders, elbows, and hands of PMR moved more widely than the control participant. 3) The PMR did not perform two subtasks at the same time. 4) The PMR repeated some subtasks. Factor 1 and 2 seem to decline the manual dexterity of PMR. Factor 3 and 4 seem to take the PMR more time to perform.
We will discuss the possibility of overcoming the problems of manual dexterity and performance speed.
This PDF is available to Subscribers Only